A non-contact armature air gap adjustment method

Abstract

The present invention relates to a non-contact armature air gap adjustment method, which belongs to the field of injector assembly. The present invention adds an observation hole to one end face of the adjustment gasket, and the observation hole is usually a plurality of evenly distributed grooves whose line of sight does not pass through the center of the circle. The non-contact armature air gap adjustment method of the present invention is mainly divided into two steps: air gap adjustment gasket selection and armature air gap detection. The present invention provides a non-contact armature air gap adjustment method, which not only reduces costs, but also prevents possible contamination of the armature plane caused by contact measurement, and is suitable for injector structures that cannot be detected by laser ranging.

Description

Technical Field

[0001] The invention belongs to the field of fuel injector assembly, and in particular relates to a non-contact armature air gap adjustment method. Background Art

[0002] Adjustment of the armature air gap is an important step in the assembly of common rail injectors. Usually, the armature air gap is below 0.1mm, and its precision is required to be extremely high. Slight differences in the armature air gap will seriously affect the consistency of the injector.

[0003] Typically, the armature air gap is measured and adjusted using the contact method during injector assembly. After the injector is assembled and before bench testing, laser ranging is often used to further verify that the armature air gap meets the required standards, looking through the through-hole in the center of the electromagnet. This process is cumbersome, and the laser rangefinders used are expensive, requiring significant labor and material costs. For injectors with a bottom-mounted solenoid valve or an electromagnet without a center hole, laser ranging cannot be used for post-assembly air gap detection. Summary of the Invention

[0004] (1) Technical issues to be resolved

[0005] The technical problem to be solved by this invention is to provide a non-contact armature air gap adjustment method to address the existing cumbersome armature air gap adjustment process and the expensive laser rangefinder used, which consumes a lot of manpower and material costs. Furthermore, laser rangefinders cannot be used to measure the air gap after assembly in fuel injectors with a bottom-mounted solenoid valve and a solenoid without a center hole.

[0006] (2) Technical solution

[0007] In order to solve the above technical problems, the present invention proposes an air gap adjustment gasket, which is used for adjusting the armature air gap. An observation hole is added to one end face of the adjustment gasket. The observation hole is a plurality of evenly distributed grooves whose line of sight does not pass through the center of the circle.

[0008] Furthermore, we design and produce a variety of air gap adjustment gaskets with different diameters and thicknesses.

[0009] Furthermore, the symmetrical grooves on the adjustment gasket are located on the same center line.

[0010] A non-contact armature air gap adjustment method includes two steps: selecting an air gap adjustment gasket and detecting the armature air gap. The armature air gap adjustment method specifically includes the following steps:

[0011] S11. First, enter the air gap adjustment gasket selection process. The injector includes: an injector body, an armature disc, and an electromagnet. A sealing seat is provided on the top surface of the injector body. The injector body is fixed to a rotating table. A downward pressing force is applied to the armature disc above the injector body so that the column in the center of the armature disc completely rests on the sealing seat.

[0012] S12. Using a profile projector, measure the distance between the armature engaging surface at the top of the armature disc and the air gap adjustment end surface at the top of the injector body. The distance between the armature engaging surface and the air gap adjustment end surface at different rotation angles is measured by rotating the rotating table to improve measurement accuracy. The profile projector includes a parallel light source and a projection screen.

[0013] S13. Add the measurement result to the armature air gap that needs to be reserved to select the appropriate air gap adjustment gasket;

[0014] S14. Place the selected air gap adjustment gasket with an observation hole on the air gap adjustment end face and sleeve it around the armature disc. Then install the electromagnet and enter the armature air gap detection process.

[0015] S15. Apply a compressive force to the top of the electromagnet to ensure that the electromagnet, air gap adjustment gasket, and injector body are completely in contact. Measure the air gap of the assembled armature through the observation hole to see if it meets the design requirements. Rotate the rotary table and measure the air gap of the armature through the observation holes in different directions to improve measurement accuracy.

[0016] S16: If the requirements are met, proceed to the next assembly process;

[0017] S17. If it does not meet the requirements, return to S11 to perform the air gap adjustment gasket selection process, reselect the appropriate air gap adjustment gasket, and perform the armature air gap test again. If the test result still does not meet the requirements, the injector body needs to be replaced.

[0018] Furthermore, in S11, a downward pressing force is applied to the armature disc above the injector body by a pneumatic or hydraulic device.

[0019] Furthermore, the rotating table rotates along the vertical center axis.

[0020] Furthermore, in step S12, a parallel light source is irradiated from one side parallel to the air gap adjustment end surface and the armature engagement surface, and the distance between the armature engagement surface and the air gap adjustment end surface is observed and measured on a projection screen on the other side.

[0021] Furthermore, in step S12, the average value of the distance between the armature engaging surface and the air gap adjustment end surface at different rotation angles is taken as the measurement result.

[0022] Furthermore, in step S15, the armature air gap is measured by a contour projector.

[0023] Furthermore, in step S15, the parallel light source passes through the grooves on the same center line and is projected onto the projection screen to form a bright band, and the armature air gap is detected by measuring the height of the bright band.

[0024] (3) Beneficial effects

[0025] The present invention proposes a non-contact armature air gap adjustment method. The present invention provides a non-contact armature air gap adjustment method, which not only reduces costs but also prevents possible contamination of the armature plane caused by contact measurement, and is suitable for injector structures that cannot be detected by laser ranging. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the air gap adjustment gasket with an observation hole according to the present invention;

[0027] Figure 2 This is a schematic diagram of selecting and matching the air gap adjustment gasket of the present invention;

[0028] Figure 3 Schematic diagram of armature air gap detection of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below with reference to the accompanying drawings and examples.

[0030] The invention relates to a common rail fuel injector, in particular to an assembly process of the common rail fuel injector.

[0031] The present invention introduces a non-contact armature air gap adjustment method, which prevents the contamination of the armature plane caused by contact measurement and is suitable for injector structures that cannot be detected by laser ranging.

[0032] The present invention improves the common annular adjustment gasket to obtain an air gap adjustment gasket, such as Figure 1 As shown. An observation hole is added to one end face of the adjustment gasket. The observation holes are typically multiple evenly distributed grooves with a line of sight that does not pass through the center of the circle. This air gap adjustment gasket is unique to the present invention and is specifically designed for adjusting the armature air gap. Similar gaskets are not found in the prior art.

[0033] Furthermore, a variety of air gap adjustment gaskets with different diameters and thicknesses are designed and produced.

[0034] Furthermore, the symmetrical grooves on the adjustment gasket are located on the same center line.

[0035] The present invention also provides a non-contact armature air gap adjustment method, which is mainly divided into two steps: air gap adjustment gasket selection and armature air gap detection.

[0036] S11, first enter the air gap adjustment gasket selection process, such as Figure 2 As shown, the injector includes: an injector body, an armature disc and an electromagnet, and a sealing seat is provided on the top surface of the injector body; the injector body is fixed to a rotating table (the rotating table can rotate along the vertical center axis), and a downward pressing force is applied to the armature disc above the injector body by a pneumatic or hydraulic device, so that the column in the center of the armature disc completely falls on the sealing seat.

[0037] S12. Use a contour projector (including a parallel light source and a projection screen) to measure the distance between the armature engagement surface at the top of the armature disk and the air gap adjustment end surface at the top of the injector body. The rotating table can be rotated to measure the distance between the armature engagement surface and the air gap adjustment end surface at different rotation angles to improve measurement accuracy.

[0038] Furthermore, a parallel light source is irradiated from one side parallel to the air gap adjustment end surface and the armature engagement surface, and the distance between the armature engagement surface and the air gap adjustment end surface is observed and measured on a projection screen on the other side.

[0039] Furthermore, an average value of the distance between the armature engaging surface and the air gap adjustment end surface at different rotation angles is taken as a measurement result.

[0040] S13. Add the measurement result to the armature air gap that needs to be reserved to select the appropriate air gap adjustment gasket.

[0041] S14, then Figure 3 As shown, place the selected air gap adjustment gasket with an observation hole on the air gap adjustment end face and put it around the armature disk, then install the electromagnet and enter the armature air gap detection process.

[0042] S15. Apply a pressing force to the top of the electromagnet to ensure that the electromagnet, air gap adjustment gasket and injector body are completely fitted together. Measure the air gap of the assembled armature through the observation hole to see if it meets the design requirements. Rotate the rotary table and measure the air gap of the armature through the observation holes in different directions to improve measurement accuracy.

[0043] S16. If it meets the requirements, proceed to the next assembly process.

[0044] S17. If it does not meet the requirements, return to S11 to perform the air gap adjustment gasket selection process, reselect the appropriate air gap adjustment gasket, and perform the armature air gap test again. If the test result still does not meet the requirements, the injector body needs to be replaced.

[0045] Furthermore, the armature air gap is measured by a profile projector.

[0046] Furthermore, a parallel light source passes through the grooves on the same center line and is projected onto the projection screen to form a bright band. The armature air gap is detected by measuring the height of the bright band.

[0047] The invention provides a non-contact armature air gap adjustment method, which not only reduces costs but also prevents possible contamination of the armature plane caused by contact measurement, and is applicable to injector structures that cannot be detected by laser ranging.

[0048] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A non-contact armature air gap adjustment method based on an air gap adjustment gasket, characterized in that: The air gap adjustment gasket is used to adjust the armature air gap. An observation hole is added to one end surface of the adjustment gasket. The observation hole is a plurality of evenly distributed grooves whose line of sight does not pass through the center of the circle. The armature air gap adjustment method includes two steps: selecting the air gap adjustment gasket and detecting the armature air gap. The armature air gap adjustment method specifically includes the following steps: S11. First, enter the air gap adjustment gasket selection process. The injector includes: an injector body, an armature disc, and an electromagnet. A sealing seat is provided on the top surface of the injector body. The injector body is fixed to a rotating table. A downward pressing force is applied to the armature disc above the injector body so that the column in the center of the armature disc completely rests on the sealing seat. S12. Using a profile projector, measure the distance between the armature engaging surface at the top of the armature disc and the air gap adjustment end surface at the top of the injector body. The distance between the armature engaging surface and the air gap adjustment end surface at different rotation angles is measured by rotating the rotating table to improve measurement accuracy. The profile projector includes a parallel light source and a projection screen. S13. Add the measurement result to the armature air gap that needs to be reserved to select the appropriate air gap adjustment gasket; S14. Place the selected air gap adjustment gasket with an observation hole on the air gap adjustment end face and sleeve it around the armature disc. Then install the electromagnet and enter the armature air gap detection process. S15. Apply a compressive force to the top of the electromagnet to ensure that the electromagnet, air gap adjustment gasket, and injector body are completely in contact. Measure the air gap of the assembled armature through the observation hole to see if it meets the design requirements. Rotate the rotary table and measure the air gap of the armature through the observation holes in different directions to improve measurement accuracy. S16: If the requirements are met, proceed to the next assembly process; S17. If it does not meet the requirements, return to S11 to perform the air gap adjustment gasket selection process, reselect the appropriate air gap adjustment gasket, and perform the armature air gap test again. If the test result still does not meet the requirements, the injector body needs to be replaced.

2. The non-contact armature air gap adjustment method according to claim 1, wherein: In the step S11 , a downward pressing force is applied to the armature disc above the injector body by a pneumatic or hydraulic device.

3. The non-contact armature air gap adjustment method according to claim 1, wherein: The rotating table rotates along the vertical center axis.

4. The non-contact armature air gap adjustment method according to claim 1, wherein: In step S12, a parallel light source is irradiated from one side parallel to the air gap adjustment end surface and the armature engaging surface, and the distance between the armature engaging surface and the air gap adjustment end surface is observed and measured on a projection screen on the other side.

5. The non-contact armature air gap adjustment method according to claim 1, wherein: In step S12, the average value of the distance between the armature engaging surface and the air gap adjustment end surface at different rotation angles is taken as the measurement result.

6. The non-contact armature air gap adjustment method according to claim 1, wherein: In step S15 , the armature air gap is measured by a profile projector.

7. The non-contact armature air gap adjustment method according to claim 6, wherein: In step S15, the parallel light source passes through the grooves on the same center line and is projected onto the projection screen to form a bright band. The armature air gap is detected by measuring the height of the bright band.

8. The non-contact armature air gap adjustment method according to claim 1, wherein: Design and produce a variety of air gap adjustment gaskets with different diameters and thicknesses.

9. The non-contact armature air gap adjustment method according to claim 1, wherein: The symmetrical grooves on the adjusting shim are located on the same center line.

Images